ObjectiveTo investigate the effectiveness and technical key points of limb salvage surgery by allotransplantation of cryopreservated vascularized bone in children and adolescents with osteosarcoma. MethodsA retrospective analysis was made on the clinical data of 21 children and adolescents with osteosarcoma receiving limb salvage surgery by allotransplantation of cryopreservated vascularized bone from their relatives between February 2004 and April 2012. There were 13 males and 8 females, aged from 7 to 16 years (mean, 12.6 years). According to Enneking stage system, 15 cases were rated as stage ⅡA and 6 cases as stage ⅡB. The tumors located at the distal femur in 10 cases, at the proximal femur in 1 case, at the proximal tibia in 8 cases, at the proximal humerus in 1 case, and at the distal radius in 1 case. Imaging examination showed that epiphyseal extension of malignant bone tumors in 7 cases. The iliac bone allograft with deep iliac vessels was obtained from their lineal consanguinity. After preservation by a twostep freezing schedule, the iliac bone allograft with deep iliac vessels was implanted into the bone defect area after tumor resection. The size of iliac bone flap was 8.0 cm×3.0 cm×2.0 cm-14.0 cm×5.0 cm×2.5 cm. Reserved joint surgery was performed on 16 cases and joint fusion surgery on 5 cases, and external fixation was used in all cases. The chemotherapy was given according to sequential high-dose methotraxate, adriamycin, and cisplatine before and after operation. ResultsAll 21 cases were followed up from 5 months to 11 years (mean, 6.4 years). At 2 weeks after operation, the erythrocyte rosette forming cells accounted for 56.7%±3.9%, showing no significant difference when compared with that of normal control (58.3%±4.3%) (t=1.56, P=0.13), which suggested no acute rejection. At 4 weeks after operation, single photon emission computerized tomography bone scan indicated that the blood supply of bone graft was rich, and the metabolism was active. At 12 weeks after operation, the digital subtraction angiography showed the artery of iliac bone flap kept patency. X-ray films showed that malunion and non-union occurred at 5 and 6 months after operation in 1 case, respectively. The bone graft healed in the other patients, and the healing time was 3.2-6.0 months (mean, 4.4 months). At last follow-up, American Musculoskeletal Tumor Society (MSTS) score was significantly improved to 26.80±2.14 from preoperative value (17.15±1.86) (t=-4.15, P=0.00). The survival rate was 85.7% (18/21) and the recurrence rate was 9.5% (2/21). ConclusionAllotransplantation of cryopreservated vascularized bone from the relatives provides a new method for the treatment of osteosarcoma in children and adolescents. A combination of allotransplantation and chemotherapy can achieve the ideal treatment effect. The correct cutting, preservation, and transplantation of the donor bone, and indication are the key to improve the effectiveness.